A Web search engine is a computer implemented system that is configured to search for information that is available on the World Wide Web and FTP servers. In operation, a search engine receives a query issued by a user and performs a search over documents indexed by the search engine based at least in part upon the query. The goal of the search engine is to provide the user with documents that are most relevant to the information retrieval intent of the user. Types of documents that can be searched over and provided to the user include web pages, images, data from news feeds, etc.
Search engines desire to provide users with most relevant search results, and utilize relatively complex algorithms to output a ranked list of documents responsive to receipt of a query. A most highly ranked document (a document believed by the search engine to be most relevant to the information retrieval intent of the user) is presented most prominently to the user, typically as the top-most search result in a list of search results. Search results believed to be less relevant to the information retrieval intent of the user when compared to the most relevant search result are presented lower in the ranked list of search results.
Accurately determining which search results are most important to the user is an extremely important task, as generally users will not analyze a large number of search results to find a document that is most relevant to the information retrieval intent of the user. Rather, if the user does not quickly see a search result that is believed to be relevant to her informational intent, the user will most likely give up searching for such information, recast the query, or attempt to use another search engine to locate desired information. As revenue is generated in search engines based upon advertising fees, it is imperative that search engines determine ranking of documents accurately with respect to information retrieval intent of a user to retain traffic and attract new users.